Flu-vaccine delays put Switzerland’s winter supply under scrutiny

About 40% of Switzerland’s ordered flu vaccine doses are facing delivery delays ahead of the 2026/2027 season, placing the timing of winter protection under closer scrutiny. The Federal Office of Public Health confirmed that certain batches will arrive late, while saying the country is not facing a general vaccine shortage.

The supply picture remains divided. The FOPH expects 60% of the ordered doses to arrive on time. Manufacturers have also indicated that enough vaccine should be available for people at greatest risk from influenza, including older adults who need a high-dose formulation.

The uncertainty concerns timing as much as volume. Swiss health authorities recommend vaccination in November because protection takes around two weeks to develop. Influenza activity usually reaches its highest level between December and February, giving people a limited window to arrange an appointment before infections rise.

Pharmacies, doctors’ practices and vaccination centres will therefore need to manage appointments around the deliveries they receive. The FOPH has not said that people will be left without access to vaccination. It has acknowledged that some delayed batches may arrive too close to the season for their effectiveness to align with peak demand.

Nearly two of the four flu vaccines ordered for Switzerland are affected by delivery delays, according to the information confirmed by the FOPH. The figure refers to vaccine products, while the federal office estimates that delayed batches represent about 40% of total doses ordered.

That distinction matters for patients and healthcare providers. A delayed product does not necessarily mean that every vaccination appointment will be cancelled. Switzerland will still receive the other products on schedule, and manufacturers expect supplies to cover the groups prioritised by health authorities.

The FOPH expects particularly reliable availability for the high-dose vaccine used for people aged 75 and older. It also anticipates sufficient supplies for high-risk people aged 65 and older. These groups face a greater risk of serious complications from influenza, making early access a key planning priority.

Availability for the wider population is also expected, although the FOPH has not yet confirmed whether every delayed batch will arrive early enough to provide protection during the most useful part of the season. Patients seeking vaccination should check with their doctor, pharmacy or local vaccination centre before booking, especially if they require a specific formulation.

The World Health Organization’s late selection of the seasonal vaccine composition helped push production schedules back, according to Enea Martinelli, vice-president of the PharmaSuisse umbrella association. Manufacturers must reformulate the vaccine each year to match the influenza viruses expected to circulate during the coming winter.

The process depends on surveillance from regions where the flu season starts earlier, including countries in the Southern Hemisphere and parts of Asia. Experts analyse circulating strains, then use that information to determine which components should go into the next vaccine. Production can only move forward once those decisions are made.

Martinelli said the World Health Organization determined the composition “relatively late in the year”, contributing to the delays now affecting deliveries to Switzerland. The same production pressure has reached other European countries, so Swiss distributors are operating within a wider regional supply chain rather than dealing with an isolated domestic problem.

The annual manufacturing cycle leaves little room for disruption. Once vaccine composition is set, manufacturers must produce, test and distribute batches before pharmacies and medical practices can begin broad seasonal campaigns. A late decision at the start of that chain can affect appointments months later.